彭相仕 张彦平 王翔宇 郑松超

摘要 对自来水厂含铁污泥进行高温热改性，得到热改性铁污泥（Thermally modified iron sludge：TMIS）吸附材料。试验研究了TMIS的最佳改性温度、吸附除磷最佳参数及其吸附除磷的动力学、等温线和热力学，进一步利用浸渍试验考察了吸附磷后TMIS对污染物的溶出效果。结果表明，TMIS最佳改性温度为400 ℃，在投加量为10 g/L，初始磷浓度为15 mg/L，pH为5，反应100 min时的条件下，磷去除率最佳，达到99.68%，吸附量为1.495 mg/g。TMIS对磷的吸附数据值符合 Lagergren 拟二级动力学模型与Langmuir 等温吸附线模型，表明吸附是以化学过程为主的单层吸附。热力学分析表明此吸附为可自发进行的吸热反应。30 d浸渍试验结果表明，吸附磷后的TMIS体系中 COD、氨氮及铁释放量均低于原污泥体系，磷释放量高于原污泥体系，但小于0.02 mg/L。

关 键 词 铁污泥；热改性；除磷；吸附

中图分类号 X705     文献标志码 A

文章编号：1007-2373（2023）03-0090-07

DOI：10.14081/j.cnki.hgdxb.2023.03.010

Study on phosphorus removal characteristics of thermally modified iron sludge

PENG Xiangshi， ZHANG Yanping， WANG Xiangyu， ZHENG Songchao

（School of Civil Engineering and Transportation， Hebei University of Technology， Tianjin 300401， China）

Abstract The thermally modified iron sludge （TMIS） has been obtained by modification of the iron-containing sludge from the waterworks with thermal. The TMIS can be used as adsorption material for phosphorus. In this experiment， the optimal modification temperature for TMIS， the optimal parameters and adsorption kinetics， adsorption isotherms and thermodynamic analysis of phosphorus removal have been studied. The dissolution effect of pollutant has been further investigated by the immersion test. The results show that the optimal modification temperature for TMIS is 400 ℃. Under the optimal conditions of dosage of TMIS 10 g/L， initial phosphorus concentration 15 mg/L， pH 5， and reaction time 100 min， phosphorus removal rate has reached 99.68% and the adsorption capacity is 1.495 mg/g. The data of phosphorus adsorption by TMIS is in accordance with Lagergren's quasi-second-order kinetic model and Langmuir isotherm model， which indicates that the adsorption is a single-layer adsorption based on chemical processes. Thermodynamic analysis show that this adsorption is an endothermic reaction that can proceed spontaneously. The 30-day immersion test results show that the release of COD， ammonia nitrogen and iron in the TMIS system after phosphorus adsorption are all lower than that of the original sludge system; the release of phosphorus is higher than that of the original sludge system， but it is less than 0.02 mg/L.

Key words iron sludge; thermal modification; phosphorus removal; adsorption

0 引言

磷是自然界重要的组成元素之一。近年来，由于含磷废水的过量排放，使得藻类大量生长繁殖，引起水质恶化，并造成环境平衡失调。因此，除磷技术已成为国内外的研究热点。常见的除磷方法主要有：生物、化学、物理吸附等多种方法[1]。其中，生物法适用广泛，但是周期长、见效慢，且初期投资和长期运行费用昂贵[2]；化学方法除磷效果较好，但所需投加的药剂较多，导致污水处理成本过高，还会使水体带金属离子的颜色[3]。吸附法操作简易，具有节约成本、污染小、效率高、循环性等优点[4]，因此受到研究者的广泛关注[5]。吸附材料简单易得，常见的主要有黏土类、金属氧化物、碳素类和废物废渣等[6]。……